Optical Allusion

I assume everyone has come across a trick of visual perception at least once. The idea is that the information the eye perceives and what the brain concludes after processing it is not objective reality. The following image is representative of an ambiguous illusion -- meaning the mind will teeter-totter between the alternative renditions.



Is it a pair of people, or a skull?

You actually may see only one or the other, or both, or neither (in that circumstance you should probably go see a doctor). Things like life experience, cultural difference, sex and age, will influence perception and as a result folks don't sense and comprehend ocular phenomena identically.

All of which leads to this:



Is it a house, or a flag?

The reason I ask is because I spoke to a man who apparently sees the former and, regardless of how many times or how long I stare at it, it sure looks like the latter to me.